Bladed axial flow rotors



May 24, 1960 E. A. STALKER BLADED AXIAL FLOW ROTORS 2 Sheets-Shea?I 1 Filed June 24, 1954 INVENTOR.l

May 24, 1960 E. A. STALKER BLADED AXIM. mow RoToRs 2 Sheets-Sheet 2 Filed June 24, 1954 INVENTOR.

United States Patent-:O

BLADED AXIAL FLOW ROTORS Edward A. Stalker, Bay City, Mich., assignor to The Stalker Corporation, a corporation of Michigan Filed June 24, 1954, Ser. No. 439,107

13 Claims. (Cl. 253-39) This invention relates to axial flow elastic fluid compressor and turbine roto'rs. j

An object of thisinvention is to provide a lrotor structure which is adaptedv to economical fabrication from sheet metal and sheet metal stampings.

Another object is to provide a sheet metal structure whose parts require a minimum number o'f jigs to support them while they are being soldered together.

Other objects will appear from the description, drawis a substantial change in pressure and density of the uid in proceeding along a rotor passage from the leading to the trailing edges ofthe blades. To sustain the fluid pressure and the change in pressure along the rotor passages, the ends of the passages must have axially directed walls.

To produce or utilize significant pressure changes in an elastic uid, the blades must have a speed relative to' the fluid at which compressibility effects become significant. It is well known that the compressibility of air becomes significant at tip speeds at and above 400 feet per second.

To produce large compressibility effects speeds in the neighborhood of the speed of sound are usually employed.

To produce roto'rs economically from sheet metal parts soldered together, the number of parts must be kept to a minimum and the parts should `be self-jigging through the use of spot welding and the employment of lintegral locating devices.

The above objects are accomplished by the means illustrated in the accompanying drawings in which- Fig. l is an axial section through a compressor incorv porating a preferred form of this invention;

Fig. 2 is a fragmentary axial section through a rotor of Fig. 1, according to this invention;

Fig. 3 is a cut-away perspective viewof`a rotor of Fig. l;

Fig. 3a is a radial view of a fragment of the rotor rim;

Fig. 4 is a fragmentary section on line 4-4 in Fig. 2;

Fig. 5 is a fragmentary section on line 5-5 in Fig. 4;

Fig. 6 is a fragmentary section on line 6-6 in Fig. 2; and

Fig. 7 is a section on line 7-7 in Fig. 2.

By way of illustration of a preferred form of the invention a compressor 10 is shown in Fig. l wherein the rotor assembly is co'mprised of a plurality of rotors or wheels 12-15 assembled in tandem relation and supported for rotation by shafts 22 and 24 in the bearings 26 and 28 respectively.

Since the rotors are similar it will be sufiicient to describe rotor 13. This rotor is comprised of the blades 16 and the hub structure 18.

Patented May 24, 1960 The rotor is housed in the case 30 which supports the stators 31-35 between the rotors. The stators are comprised of the blades 36-40 supported on the case 30.

Each rotor or wheel as shown in Figs. 2-4 is comprised `of the side plates 40 and 42 each having a plurality of blade stems 44 and 46 spaced peripherally and integral with a respective side plate. Each pair of axially adjacent stems extend spanwise within a blade envelo'pe 50 and are fixed to opposite walls thereof. See Figs. 3 and 7 particularly.

Where the blades are4 placed closely together a second set of blade stems are interposed between those carried on Ythe side plates. These stems 51 and 52 are integral respectively with the annular rings 53 and 54 shown'in Figs. 2 and 3.

Thel hub 56 is separately fabricated and fixed prefer- 'ablyby fused metal to the side plates or other disks;A

The side plates each have a large central opening 55v .whose edges are fixed to the hub elements 56o and 56h I:which are employed for stacking the wheels in axial relation as shown in Fig. .1. Through bolts 60 passing through holes 61 and end disks 64, and 66 hold the rotors in stacked relation with'the teeth 62 of one vclutch'meshing with the teeth of the adjacent clutch.

The end disks are fixed to the shafts 22 and 24 which mount the rotor assembly in the bearings 26 and 28.

The rim means 70kcomprises the two sheet metal parts lformed as stampings or pressings 72 and' 74 whose lower legs 76 and 78 are bonded to the side plates 42'a'nd 40 respectively. The axially directed flanges 80 and 82 close the spaces between the blades and between the leading edges L E. and the trailing edges T.E. to sustain changes in iiuid pressure between these edges. Y

The rings 53 and 54 are bonded to the insidesurfaces kof the side plates 40 and 42 as shown particularly in Figs. ,2 and 3. f

The ,side plates are stiffened by the stiffener disks or plates 84 and 85 (Figs. 2, 3 and 4) extending radially vand fixed to the opposite side plates at radially spaced locations. As shown particularly inFigs. 2 and 4 each stiffener plate is fixed to a flange vand 102 of the hub element 56. Each stiffener plate .is fixed tothe other at localities and 107 and to the rings 53 or 54 at localities 104 and 106. The stiffener plates are corrugated at theirperimeters to accomplish the contact with' the rings j 'at 104 and 106.

At 105 and'107 (Figs. Zand 5) the `stitfener plates are telescopically related. The projection 112, for' instance, on plate 84 fits into the tubular projection 113 of plate 85 with very small clearance'of the order required for 'j the ilow of the solder, by capillary action, in contact with both surfaces. Y

yEach stiffener plate is xed to the side plates at` joints 108 and 110. p

The stems are illustrated by stems 44 and 46 which have flanges fixed to the legs 76 and 78.4

The stiffener plates have lightening holes 149 and 150,

Figs. 2 and 3. Y

As shown in Fig. 7, stern 44 is bonded or fused to the upper or convex wall 90 of the blade envelopeiand stem 46 is bonded to the lower wall 92.

The advantages of this rotor structure will also' b apparent from the assembly procedure.

The side plate 40, ring 51 and the rim .part 72 are spot welded together as a preparation for soldering. The stiffener 84 is also spot welded on at 100, 104 and 108.

3 It will be observed that all this spot welding is readily accomplished because the 'structure is open for operations on both sides.

In like manner side plate 42 and its associated parts are spot welded together.

Also the clutch anges 100 and 102 are spot welded to their respective side plates as shown in Fig. 2 after placing solder wire in the grooves or recesses in the parts as at 178.

The two side plate assemblies are next brought together with the beveled edge of flange 82 tting below the beveled edge of flange 80 and above the stop plate 180 which has previously been fixed to ange 82. The projections 112 and 113 are brought into registration preferably with copper paste between their surfaces to provide for soldering them together-although other forms of solder such as wire or copper plating may also be used.

The blade envelopes are .prepared in a separate operation and are slid over the stems through the openings 184 inthe rim.

The assembly is next placed in a suitable fixture and passed through a furnace to consolidate the joints. Since the parts of the two subassemblies are spot welded together and since they in turn are secured relative to each other in part by the blade envelopes only a relatively simple fixture is required. It mainly has to support the Y tips of the blades.

Telescopically related surfaces such as those of parts 112 and 113 are particularly useful in joining rotor parts in localities which are not readily accessible for control of the relative positions. For successful soldering, particularly furnace soldering, it is important that the lapping surfaces to be soldered have a limited clearance of about 0.003 in. or less. It would be diflicult to assure such clearances between parts 84 and 85 at a locality such as 107 when the two halves of the rotor are brought Vtogether. The lapping surfaces of 112 and 113 which have limited movement in the axial direction parallel to these surfaces always provide the proper soldering clearance independently of the axial movement. Thus internal parts of the rotor can advantageously utilize this lapping or telescopic device for providing proper soldering clearance.

It will now be clear that I have provided a unique rotor construction of light weight sheet metal construction which can be economically fabricated.

While I have illustrated specific forms of the invention, it is to be understood that variations may be made therein and that I intend to claim my `invention broadly as `indicated by the appended claims.

I claim: Y

1. In combination in an axial flow compressor rotor, axially spaced side plates, a separately fabricated hub positioned between said plates and bonded to each said plate centrally thereon, a stiifener disk fixed to each said side plate at radially spaced localities, said stiffener disks being positioned between said side plates and being bonded to each other at radially spaced localities, and a plurality of axial ilow blades peripherally spaced about said side plates and supported thereon, saidr rotor including means adjacent to the root ends of said blades closing the space between said blades and between said side plates.

2. In combination in an axial flow compressor rotor, axially spaced side plates, a separately fabricated hub positioned between said plates and bonded to each said plate thereon, a stiifener disk iixed to Veach said side plate at radially spaced localities on the inside surface thereof, said stitfener disks having axially directed lapping surfaces arranged for limited relative movement in the axial direction with limited clearance therebetween upon assembly providing for the joining of said assembled sur- 'faces by solder, and a plurality of axial flow blades peripherally spaced about said side plates and supported thereon, said 'rotor including means adjacent to the root ends of said blades closing the space between said blades and between said side plates.

3. In combination in an axial ow compressor rotor axially spaced side plates, a hub positioned between said plates and bonded to each said plate thereon, juxtaposed stitfener disks having contiguous portions alternated with spaced portions, said contiguous portions being bonded together and said spaced portions being fixed to said side plates, and a plurality of axial ow blades peripherally spaced about said side plates and supported thereon, said rotor including means adjacent to the root ends of said blades closing the space between said blades and between said side plates.

4. In combination in an axial flow compressor rotor, axially spaced side plates, a hub positioned between said plates and bonded to each said plate thereon, juxtaposed stitener disks having adjacent portions alternated with spaced portions, said spaced portions being bonded to said side plates, said adjacent portions having tubular parts telescopically related to provide closely tting lapping surfaces for fusing together by solder therebetween, and a plurality of axial flow blades peripherally spaced about said side plates and supported thereon, said rotor including means adjacent to the root ends of said blades closing the space between said blades and between said side plates.

5. In combination in an .axial flow compressor rotor, axially spaced side plates, a stiffener disk fixed to each said plate at .radially spaced localities, said disks being positioned between said plates and being bonded to each other at radially spaced localities, and a plurality of axial ow blades peripherally spaced about said side plates and supported thereon, said rotor including means adjacent the root ends of said blades closing the space between said blades and between said plates.

6. In combination in an axial llow compressor rotor, axially spaced plates, a stiiener means comprising radially and peripherally spaced elements extending axially and peripherally between said plates and terminating at the inside surface thereof in llapping relation therewith, said stiiener means being bonded to each said plate at radially spaced localities and being peripherally xed to each other in 'areas between said plates and spaced axially therefrom, and a plurality of axial ow blades peripherally spaced about said side plates and supported thereon, said rotor including means adjacent the root ends of said blades closing the space between said blades and between said plates.

7. In combination in an axial flow bladed rotor for a uid machine vfor exchanging force with an elastic duid, said rotor being adapted for rotation about an axis developing centrifugal forces at the root ends of said blades and substantial axially directed forces, a rim means extending peripherally between said blades and having radially inwardly extending parts, a plurality of axial llow blades peripherally spacedfabout said rim means with their root ends adjacent thereto, said blades-extending radially outward from said rimmeans, a sheet metal plate secured to said blades and to said inwardly extending parts of said rim means to sustain said centrifugal forces, and astiiiener disk secured to said plate adjacent to said inwardly extending parts of said rim means and spaced axially from said plate by distances increasing radially inward of said rim means to sustain said axial loads.

8. In combination in an axial ow bladed rotor for a uid machine'having a hub for exchangingforce with an elastic Huid, said rotorbeing 'adapted for rotation about an axis developing centrifugal 'forces at the root ends of said blades and substantially axially directed forces in the operation of said rotor, ,axially spaced side plates each having a plurality of blade stems integral therewith and spaced peripherally thereabout, a plurality of blade envelopes `enclosing said stems and fixed thereto for supporting said envelopes against said centrifugal forces, said rotor developing a substantial change in density and pressure in said fluid fiowing between said blades, and rim means extending between said blades and from front to rear of said rotor to sustain said change in pressure, and axially spaced stiifener disks secured to said blade stems adjacent said rim means and to said hub, said dis-ks being enclosed within said side plates and secured to each other to sustain axial loads.

9. In combination in an axial flow bladed rotor for a Huid machine for exchanging force with an elastic fluid, said rotor being adapted for rotation about an axis developing centrifugal forces at the root ends of blades and a substantial change in density and pressure in said uid owing between the blades of said rotor in the operation thereof, axially spaced side plates, rim means in said rotor, and a plurality of axial flow blades peripherally spaced about said rim means and extending radially outward therefrom, each said blade extending radially inwardof said rim means and having radially inner parts secured to said side plates for sustaining said centlifugal forces, said rim means comprising a front ring and a rear ring having axially directed flanges abutting one another to substantially close the space between blades and between the front and rear sides of said rotor to sustain said change in pressure, each said ring lhaving a radially directed leg fixed to a side surface of a said plate, and at least one stiffener disk secured by fused metal in ilat face to face contact with an adjacent side plate at a plurality of radially spaced areas inwardly of said rim means for sustaining axial loads. v

10. In combination `in an axial ow machine for exchanging force with an elastic iluid, a case, a high speed bladed rotor mounted for rotation in said case developing a substantial change in pressure and density of said tluid flowing between the blades of said rotor and substantial centrifugal and axially directed forces in said rotor in operation thereof, said rotor comprising axially spaced side plates, rim means positioned about said plates and having radially directed legs each fixed to a respective said side plate, a plurality of axial ow blades peripherally spaced about said rim means and extending outward therefrom, each said blade extending inwardly of said rim means between said legs and being secured to said legs and to said side plates to sustain said forces, and stiffener means positioned between said plates comprising spaced elements extending axially and peripherally therebetween and fixed thereto in at face to face relation at a plurality of radially spaced areas to sustain said axial components of force.

ll. In combination in an axial flow compressor rotor, axially spaced side plates, a hub positioned between said plates and xed thereto, a plurality of axial projections for each said side plate xed thereto at radially spaced localities on the inside surface thereof, certain of said projections on opposite said side plates being opposite each other, said opposite projections having axially directed lapping surfaces arranged on assembly for relative movement in the axial direction and limited movement therebetween in a direction transverse to the axial direction providing limited clearance between said lapping surfaces for the joining of said lassembled surfaces by solder, and a plurality of axial flow blades peripherally spaced about said side plates and supported thereon, said rotor including means adjacent to the root ends of said blades closing the space between said blades and between said side plates enclosing said projections from radially inward access thereto.

12. In combination in an axial ilow compressor rotor, a hub, a pair of subassemblies each including a side plate having a plurality of peripherally spaced blade stem parts projecting radially outwardly therefrom, separate rim means secured to each saidside plate and having an axially directed flange extending peripherally between ysaicl blade stems and over a part of the axial extent thereof, each said rim means having apart overlapping and secured by fused metal to the wall of the adjacent said side plate, means for fixing said subassemblies together upon said hub with said side plates axially spaced apart and said separate rim means meeting to form a closed rim surface at the roots of said blades, said blade stem parts on one said plate cooperating with those on the other to form pairs, and blade envelopes received over said blade stem pairs and extending inwardly of said rim means.

13. In combination in an axial flow compressor rotor, a hub, a pair of subassemblies each including a side plate having a plurality of peripherally spaced blade stem parts projecting radially outwardly therefrom, separate rim means secured to each said side plate and having an axially directed ange extending peripherally between said blade stems and over a part of the axial extent thereof, each said rim means having a part overlapping and secured by fused metal to the wall of the adjacent said side plate, a stiiener disk secured to each said side plate at radially spaced positions thereon, means for fixing said subassemblies together upon said hub with said side plates axially spaced apart and with said stiiener disks enclosed therebetween and said separate rim means meeting to form a closed rim surface at the roots of said blades, said blade stem parts on one said plate cooperating with those on the other to form pairs, and blade envelopes received over said blade stem pairs and extending inwardly of said rim means.

References Cited in the le of this patent UNITED STATES PATENTS 1,210,978 Parsons et al. Ian. 2, 1917y 2,604,298 Bachle July 22, 1952 2,678,537 Stalker May 18, 1954 2,801,071 Thorp July 30, 1957 FOREIGN PATENTS 276,510 Switzerland Oct. 16, 1951 289,799 Switzerland July l, 1953 702,740 Great Britain Jan. 20, 1954 991,982 France June 27, 1951 

